The three levels of spelling lists and practice activities in Essentials enable teachers to provide the right level of difficulty for each student.
Students should be learning how to spell words they have not already mastered, so that they need to think carefully about the sounds, the phonograms, and the spelling rules and rely on the cues and clarifications from the teacher; if the list is too easy, they will miss valuable practice applying the skills they have been taught.
However, students should also not be overwhelmed or struggling with the words, so it is important not to use a list that is too difficult as well. In addition, if a student does not know how to spell many of the high-frequency words taught in the easier lists, or struggles to read them, developing fluency with these common words should be the priority before working on more advanced words.
If a student who is in Level B or C is struggling, it is always appropriate to consider dropping down to an easier level. You do not need to go back to the beginning before doing so; simply change levels where you are. If you do decide to switch, when you encounter an occasional spelling word that the student doesn't know in a dictation sentence or other spelling activity, simply go through the spelling analysis process to teach the student about the word and then continue.
We do not recommend moving up midway through, especially from Level B to Level C. It works best to complete all 30 Units of Essentials at one level and then, if you would like to review for deeper mastery and introduce more advanced levels of application, repeat from the start using the next level up. It can be challenging and confusing to switch mid-stream, because dictation sentences, vocabulary lessons, and other activities are designed for students who have learned all the previous morphemes and spelling words for that level.
If you do determine as you progress through the curriculum that the level your student is using is far too easy and the student would have been more appropriately challenged at a different level, and you decide to switch, be prepared to teach previously taught spelling words and morphemes that the student has not learned as you encounter them.
Another option is to stay at the same level but introduce a few "challenge words" from a more advanced spelling list in each unit and teach them through spelling analysis.